For a communication system using an unlicensed carrier, it may be suggested to avoid use of an unlicensed carrier which is being used by an existing station, otherwise mutual interference of systems may be introduced. Therefore, in some countries, such as Europe and Japan, a Listen Before Talk (LBT) function is compulsively required to be supported for an unlicensed carrier. That is, before a certain unlicensed carrier is used, a Clear Channel Assessment (CCA) technology is executed. If it is found that certain equipment is using the unlicensed carrier or detected signal energy exceeds a CCA threshold, access is delayed; and if it is found that a channel is idle or the detected signal energy is lower than the CCA threshold, the unlicensed carrier can be occupied.
A power control method in a related technology is only set from the point of a single cell, and does not consider a carrier sharing requirement of an unlicensed carrier scenario. Therefore, it is needed to provide an unlicensed carrier power control solution capable of increasing using opportunities of an unlicensed carrier under the condition of considering the carrier sharing requirement of the unlicensed carrier scenario.